Heel



F. R. KEITH July 21, 1936.

HEEL

Filed NOV. .24, 1934 Patented July 21, 1936 UNI TE D 1 S TATE S PATENT OFFICE v HEEL 2 Frederick R. Keith, 'Randolph, *-Mass.

.. ..-App1ication November 24,1934, SerialNo. 754,652

"8. Claims.

. {The present invention relates toshoe heels, and

q more particularly to shoe. heels ,of theresilient or.

. rubber type. In spite of the fact that resilient or rubberheels ,5 are morepopular than are leather heels and are much more. frequently .foundion shoes today, in 1 onerespect rubber heels are less satisfactory than i ...are leather heels. If a new shoe provided with a leatherheel berplaced upright by itself on a 'iiattsurface, almost invariably the entire'bottom ofthe heel and aportion of the soleengage that. flat" surface. If, however, a new or newly repaired shoe provided with a. rubber heel be so placedon a flat. surface, almost invariably the onlyportion of. the heel which engagesqthe flatsurface is theportion in the vicinity of the bot-..

tom of the breast, .Stated in another way, viewing such a shoe from its side, a rearwardly widening, wedge-shaped gap will beseen bounded .the pressure, on the back. of'the shoe be then.

by the tread surface of.the,heel and thesurface. upon which the heel rests: This;construction causes the heel to be pivoted on thebreast region of. its bottom. Bypressing down .upon, the back of the shoe, the entire shoemay be rocked backward on the heel breast region as a pivot until the .entire bottom of the heel engages the supporting surface, ,causingjhe entiresole to rise. above such surface .andgcompletely, clear it. If.

1 Weight causes the;wedge;-shaped gapto'disappear, or nearly so'." Stated innan other way,gthe

force of the wearers weight. causes the heel to.

be particularly .noticedhere that this compression is not uniform. Instead; it is greatest in*the. vicinity of,the breast ofqthe'heel and decreases rearwardly. This greatest compression in the. vicinity of the breast has a most importanteffect upon the comfort with whichthe; shoe heel 'sup- 1 ports the heel of the foot.

It was intended by nature that when a person stands on both feet; the'full'force of his weight should; fundamentallypbe distributed between bercles of the os calcis or-bottom ofthe heel bone of each foot. -When a'person stands in his bare feet-this is precisely what occurs if his feet are normal. As a: matter ofanatomygin'advance of the plantartubercles of the oscalcis there is a rise inthebony-structure,forming part of the longitudinal arch of :the foot;. It-was never intended bylnature. that this. rise and the flesh beneath it should be a..base or terminal support for-the weight of thebody, that is, should be a substitute a'for. the plantar tubercles of..the s calcisbut in the wearing of shoes provided with rubber heels .such. asub'stitutiondoes. take-place.

If a shoe beexamined in connectionwith the anatomy of thehuman foot, itwill. be .seen that :the breast of the shoe. heel lies well forward of .sthat portion ofthe body of the. shoe heelwhich underliesthe plantar tubercles. of. the os calcis when the-shoe iswworn. In fact, it will be seen that the (breast region. ofathe heel. lies beneath --the --riseof the: longitudinal --arch of the foot which is. advance. of the plantar tubercles.

From theseobservations on heel compression and .shoe'and footlstructure, it follows thatwhen'ga person stands in shoes providedwith rubber heels, .the principalreasonwhy-supportis given the 1plantar.tuberclesdirectlyis thatathe. portion of :the. foot which underlies the rise of the arch in advance oftheplantar tubercles presses down so hard upon and compresses. thexbreast region of therubber. heel as to bringthe vtread-surface portions thereof whichliebehindlthe breast region. down into contact with the ground.

-- Theunhealthy situation presented by suchshoe construction is obvious. "The weight of the body is thrown :directlylupona part ofthe foot never intended to--. support. that -weight. directly, and strains and aches :result. f The .harm ofthis great compression ofv the breast-region of a rubber heel .can be easily. appreciatedby stamping the feet so that the heel andsole strike the ground simultaneously. The compression of the breast be compressed so, thatfalli or nearlyall of' its, tread surface engages the ground." But it is to stamping-the feet, occur with every step a wearer Qtakes throughout the day.

' With a view tocOrrecting this" situation, it is the principal object of the present invention to provide a .resilient or rubber shoe heel by the use of which the force of the wearers weight is directed downward properly. through the planar tubercles ofthe os calcis, theportion of .the heel and supported by the balland the plantar tuwhichnature intended should receive andisupport-the wearers weight. Stated in another way, it is the principal object of the present invention toprovide 'a'resilient or rubber shoe-heel of such naturethat it supports the human'heel when in a shoe in a manner substantially identical with that in which the ground supports the human heel when no shoe is worn.

To the accomplishment of this object and such others as may hereinafter appear, the various features of the present invention reside in certain constructions, combinations, and arrangements of parts fully described hereinafter and then pointed out in their true scope in the appended claims.

The various features of the present invention will be readily understood from an inspection of the accompanying drawing, illustrating thebest form of the invention at present known to the inventor, in which,

Figure 1 is an underside plan of my heel construction;

Fig. 2 is a front (breast) elevation, showing the heel secured to the heel base of a shoe;

Fig. 3 is a vertical section taken along the line 3'3 of Fig. 2;

Fig. 4 is a side elevation of a shoe provided with an ordinary rubber heel, the shoe being shown resting by itself upon a flat surface; and

Fig. 5 is a side elevation of the shoe illustrated in Fig. 4, but showing it tilted back to cause the entire tread surface of the heel to engage the supporting surface.

Referring to the drawing, the illustrated embodiment of the present invention comprises a heel body 1 which is preferably made of some suitable rubber compound, though other suitable resilient materials may be used, and is provided with the usual nail holes 8 and nail-anchoring washers 9 for receiving nails I 0 by which it is secured to the heel base ll (Figs. 2 and 3) of a shoe. Except for the region in the vicinity of the breast 13, in the formation of which region my 7 invention lies, the heel may be formed from its attaching surface l4 through to its tread surface [5 in the usual solid manner, attention being called to the fact that this is true of the back of the heel, which strikes the ground first in walk ing, and is also true of the more or less central area or region A which underlies the plantar I tubercles of the os calcis of the wearer.

Having particular regard to Figs. 1, 2 and 3, it will be seen that in the vicinity of the breast 13 a portion of the heel body is removed or cut away from the tread surface I5, leaving an arch l6 which extends downward transversely of the heel, as shown in Fig. 2, from a central breast point above the plane of the tread surface l5, and terminates short of the opposite ends of the breast I3 so as to leave narrow, tread surface portions or runs l1 and I8 at the opposite end portions of the breast. As shown in Fig. 3 the arch l6 also extends downward longitudinally of the heel from the breast l3, and terminates rearwardly at the tread surface l5 at a point marking the forward limit of the central region A. It will be appreciated'that since the arch I6 is an arch of the type stated, its line of merger with the tread surface l5 comprises an arcuate edge l9 which causes the runs l1 and I8 to flare rearwardly, As shown in Figs. 2 and 3, the arcuate edge I9 is preferably rounded or convex and is not sharp. Stated in another way, the arch I6 is itself slightly concave, but gradually merges into the tread surface l5 along an arcuate, convex edge l9. By reason of this construction the tread surface (Fig. 1) is, in effect, yoked at its breast end, the yoked ends being the breast region runs or portions l1 and I8 of the tread surface [5.

As indicated in Figs. 1, 2, and 3, the arch l6 comprises a surface separate from, merging with, the tread surface, and the separate surface or arch I6 is disposed above the plane of the tread surface IS. The arch It may be out or gouged from a solid heel, or the entire heel may be molded so as to form the arch it. As a commercial matter, it is obvious that molding is the preferable method of manufacture.

With this construction, it will be seen that whereas the body l of the heel has a normal or given resiliency, the tread portions or runs I! and I8 have a greater than normal resiliency, decreasing in the direction of the back of the heel.

This increase in resiliency is caused by the fact i.)

that the body material between the runs H and I8 has been removed, allowing for lateral expansion in two directions under pressure, which would not be the case if the entire breast region of the heel extended down to the tread surface l5.

To consider Figs. 4 and 5, it has been stated above that Fig. 4 illustrates a shoe provided with a rubber heel 2B of ordinary construction, i. e., with no part of its breast portion removed. Figure 4 brings out that when such a shoe rests upon a flat surface 21 the breast region 22 is a pivot, behind which there is a rearwardly widening wedge-shaped gap B. The shoe may be swung back on the pivot 22 to the position shown in Fig. 5, in which case the gap B disappears, the entire tread surface of the heel engages the surface 2 I, and the sole 23 clears the surface 2 I.

If a person stands in shoes such as shown in Figs. 4 and 5, the breast region or pivot 22 is flattened and compressed under the influence of the wearers weight, and the portions of the tread surface which lie behind the pivot 22 are forced against the ground, causing the gap B to disapapear, or nearly so, depending upon the weight of the wearer. But it is to be particularly noticed in this connection that this compression of the pivot 22 is not caused by the rearward rocking transition from Fig. 4 to- Fig. 5, because when a person stands in his shoes the soles thereof engage the ground as well as the heel. Instead, this compression of the pivot 22 is caused by the fact that the weight of the body acts downward through the leg and ankles along a line lying more or less over the breast or pivot region 22 of the heel. Since the plantar tubercles of the 0s 5 calcis lie behind this breast or pivot region 22, it follows that the weight of the body does not and can not act directly through the plantar tubercles to compress the breast or pivot regions 22. Instead, this compression is caused directly only 5 by the weight of the body acting through the bony arch portion and the underlying flesh which lie forward of the plantar tubercles. As a consequence the weight of the body causes abnormal pressure and strain on portions of the foot which 60 a person is standing still or is walking, and that the bony arch portion and the flesh in advance of the plantar tubercles are not called upon to support the weight of the body directly. When a person stands in shoes provided with resilient 75 heels such as I have disclosed, the breast region jof the tread surface I compresses under a relaof] the breast reg tively small amount O'fpressure because that twonarrow r'uns I1 and I8 at the; opposite ends ion and thereforehas greater resiliency than-has the rest of the heel. [As a consequence, theweight of thebody is' borne almostnentirely by-the plantar tubercles of the os calcis of each foot,- that is, is borne almost entirely by the central area or regionA' (Figs. 1 and the ground. At this precise moment the sole is 3) of the shoe -heel andnot almost thebreast region as would be the case if the entire breast region extended down to the plane of the tread surface I5.

In walking, asimilar situation appears, varied. only by the fact that the direction of the force of,the wearers weight shifts from the back to the breast of the heel asthe wearer first strikes the ground with the back of his heel and then continues. the movement of his step until the heel leaves the ground. After the initialstriking ofthebackpf the heel against theuground, the entire tread surface of the heel next contacts stillclear of the ground and the weight of the body is not. yet forward enough to cause appreciable compression of the heel breast region. I s Statedin another way, u jweare'rs weight is,directly over the breast region .of his heel, theweight .Qb y' the central area at the instant before the of the body is supported or region A. As the body continues ,to move forward, theweight of the I and the sole.

wearer is next directlyoverjthe breast region and isthen supported byboth thebreast region In these lasttwo phases the runs I1 and, I8,are considerably compressed just as ..the.breast region of an ordinary rubber heel is compressed in the same .,..,noticed that since the runs phases. But it is to be I] and I8 are more resilientthan the rest oftheheel, they compress under much less pressure. Stated in another way, ..the runs I1 and. I3 have relatively little resist- ,ance to compression and therefore yield readily .under thewearers weight. The bony arch rise and the underlying flesh which overlie the breast region and in advanceof these plantar tubercles .the area or region thus. do not bear the brunt of the ,wearers weight.

. The arch I6 lies in advance of the portion of Awhich directly underlies the plantar tubercles of the os calcis so that when the 8 heel and the sole of the shoe simultaneously en- .gage the ground, theplantar tubercles will have an equally firm support in all directions. Since the arch I6 merges with the forward portion of the area or region A of the tread surface I5, and rises in the direction of the breast, it will be seen that the resiliency of the runs I! and I8 increases in the direction of the breast, being greatest at the breast and reduced to an amount equal to that of the body of the heel where the runs I1 and I8 merge with the central area or region A. With this construction, as the weight of the wearer shifts from the central area or region A to a point over the breast region, the breast region gives to an increasing degree, and the convexity of the edge I9 aids in imparting a smooth continuity to this yielding.

While I have shown the surface I6 to be both transversely and longitudinally arch shaped so as to provide an arcuate edge I9 and therefore two tread surface runs I1 and I8 at opposite ends of the breast region, I wish to point out entirely by breast portion of the heel since they may be spaced therefrom without destroying their yielding function. It is preferred, however, to locate the runs I! and I8 as shown because this construction simulates the appearance of the sides of an ordinary heel.

Looking at my improved heel in a different light, I have disclosed it as being of solid rubber throughout. I wish to point out, however, that the present invention is well adapted foruse with heels provided with a central screen or'with a plate such as disclosed in my Patent No. 1,426,- 198, August 15, 1922. The surface I6 andthe thread surface runs I1 and I8 do not interfere with the use of such a screen or plate, and in fact improve a rubber heel so provided. Moreover, my improved heel has been illustrated in Figs. 2 and 3 as secured to the heel base II of -a shoe for the purpose of avoiding any confusion that might arise from a showing of a heel provided with a scooped or rand effect attaching surface. When a heel is secured to its heel base, such attaching surfaces assume the planiform appearance indicated for the attaching surface I4 in Figs. 2 and 3, and as such attaching surfaces form no part of my invention, they have.not been shown. It should be pointed out, however, that as with the internal screen or plate, the arch I6 and the tread surface runs I1 and I8 may be used on a heel having a scooped or rand effect attaching surface, and it is in fact contemplated that they should be so used.

What is claimed as new is:

1. A heel for a shoe comprising a resilient body portion, and a second body portion having a resiliency greater than that of the first body portion, said first body portion extending forwardly from the back of the heel and terminating in an area adapted to underlie the plantar tubercles of the os calcis, said second body portion extending from one side of the heel to the other at its breast and also extending rearwardly from the breast to merge with said first body portion at said area,

, the greater resiliency of said second body portion body portion extending forwardly from the back of the heel and terminating in an area adapted to underlie the plantar tubercles of the os calcis, said second body portion extending in its entirety from one side of the heel to the other at its breast and extending rearwardly therefrom to merge with said first body portion at said area, the tread surface of said second body portion merging at said area with the tread surface of said first body portion, the part of the under side of said second body portion not provided with a tread surface being spaced above the plane of the tread surfaces from the breast to said merging area, and the greater resiliency of said second body portion decreasing rearwardly to a condition of equality with that of said first body portion at said merging area.

3. A resilient heel for a shoe provided with a 'yoked tread surface and with a second surface disposed above the plane of said tread surface, said second surface extending transversely of the heel between the tread-surfaced portions formed by the yoking and also extending longitudinally of the heel between the breast thereof and the portion of the tread surface marking the termination of the yoking, said tread surface and said second surface merging into each other along a convex edge all portions of which lie in that part thereof adapted to underlie said plantar tubercles, and a body portion, merging with all of said tread-surfaced portions, disposed above the tread surface.

5. A heel for a shoe comprising a resilient tread-surfaced portion, other tread-surfaced portions having a resiliency greater than that of said first portion, the tread surfaces of said portions lying in a plane, and an additional portion, said first portion being adapted, in part, to underlie the plantar tubercles of the os calcis, said other tread-surfaced portions comprising spaced runs extending rearwardly from the breast of the heel to points of merger with said first portion, said points of merger being in ad-, Vance of that part of the first portion adapted to underlie said plantar tubercles, the resiliency of said runs decreasing rearwardly to a condition of equality with that of said first portion at said points of merger, and said further portion being integral with said tread-surfaced portions and overlying the space between said tread-surfaced runs, the under surface of said further portion merging with said tread-surfaced portions at said area of merger but being otherwise spaced therefrom and lying above the plane of said tread surfaces.

6. A heel for a shoe comprising a resilient tread-surfaced portion, other tread-surfaced portions having a resiliency greater than that of said first portion, the tread surfaces of said pcrtions lying in a plane, and an additional portion,

said first portion comprising the greater part of the body of the heel and being adapted, in part, to underlie the plantar tubercles of the os calcis, said other tread-surfaced portions comprising spaced runs extending rearwardly from the breast of the heel to an area of merger with said first portion, said runs being narrowest at the breast of the heel and increasing in width in the direction of said area of merger, said area of merger lying in advance of that part of the first portion adapted to underlie said plantar tubercles, and said further portion being integral with said tread-surfaced portions and overlying the space between said tread-surfaced runs, the under surface of said further portion merging with said tread-surfaced portions at said area of merger but being otherwise spaced therefrom and lying above the plane of said tread surfaces.

7. A heel for a shoe comprising a resilient body portion having an attaching surface and a tread surface a portion of which is adapted to underlie the plantar tubercles of the os calcis, and a second body portion having an attaching surface extending from one side of the heel to the other at itsbreast and merging rearwardly with the first named attaching surface, said second body portion also having spaced runs provided with tread surfaces, respectively, which extend rearwardly from the breast of the heel and merge with the first named tread surface at points in advance of that portion thereof adapted to underlie said plantar tubercles, the part of the second body portion located between said runs and beneath the attaching surface having an under surface located above the plane of the tread surfaces of said runs and extending transversely therebetween, said under surface terminating rearwardly at the tread surface of the first body portion.

8. A resilient heel for a shoe comprising a tread-surfaced body portion adapted to support that part of the wearers weight which is directed through the plantar tubercles of the os calcis, spaced tread-surfaced portions extending rearwardly from the breast of the heel and merging with said body portion at points in advance of that part thereof adapted to underlie said plantar tubercles, the tread surfaces of all of said portions lying in a plane, and a portion disposed above the plane of said tread surfaces, said portion extending across the heel at the breast from one of said spaced tread-surfaced portions to the other and extending rearwardly from the breast to merge with said body portion at its tread surface.

FREDERICK' R. KEITH. 

